The devices of the branch type have in common the fact that they are designed to be inserted into an opening in a main pipeline to provide a point at which the pipeline can be branched without having to shut down the pipeline and open it to insert a tee or the like.
The variety of devices to which this invention apertains is the "heel and toe" rocking insertion device, in which projections on the device, which, along with the device itself, are collectively longer than the widest diameter opening in the main pipeline. They are first rocked backward such that a first lug can enter the opening, and then the device is moved forward so that the second lug can be set down into the opening, whereupon the device is then centered in the opening and the inserted lugs can grasp the interior wall of the main pipeline and be used to lock the device into place when a threaded locking means is utilized.
Such "heel and toe" devices are common in the art but those currently available suffer from many problems which hinder their use.
Such devices can be found, for example, in U.S. Pat. No. 377,506, issued Feb. 7, 1888 to Whiter, in which there is disclosed a coupling for boiler tanks, and the like. This coupling is designed to be inserted into a hole in the boiler plate. The design of the device is such that it is shouldered at the point that it meets the interior edge of the hole in the pipe in order to prevent the device from rotating or turning in the hole. The locking means is shown therein as "D" and it should be noted that there is no provision for allowing the coupling to be a branch point, i.e. there are no threads on the external surface of the device. Further, it should be noted that the device extends significantly into the interior of the boiler tank, which would not be of great benefit if the device were to be used as a branch point in a main pipeline as it would tend to significantly interfere with the flow of the liquid being passed through the main pipeline.
In a further disclosure, Westphal, in U.S. Pat. No. 1,049,283, issued Dec. 31, 1912, there is shown a pipe joint that is similar to the Whiter device, in that it is designed to be used in a boiler tank. It is noted that the lugs are so designed that they can have, in one embodiment, inclined surfaces in order to engage the interior edges of the hole in the tank plating. This device also projects into the interior of the tank and makes no provision for the passage of liquid if used in a main pipeline.
In U.S. Pat. No. 1,355,450, issued Oct. 12, 1920, there is shown a device similar to the Whiter and Westphal devices, which is a device for use in a tank or the like. It is designed with a rather large, deep notch in one side of the coupling. This notch allows the coupling to be slipped into the opening in the tank plating, and then allows the coupling to be moved sideways in order to move the rest of the device into the opening. With the device in place, there is placed thereon, a packing ring, and then a collar. The collar is designed with enough length to fit down over the notch and cover it so that the fitting remains leakproof. The collar is then compressed down over the packing ring by the used of a threaded nut. It should be noted that the bottom of the device is designed with an elongated lug 3 which will help retain the device in the opening. However, the elongated lug 3 provides a barrier to the free flow of liquid if it were to be used in a main pipeline. Further, the device does not seem to have any means of controlling the rotation or turning of the device in the opening.
A device similar to the Carlson device is shown in U.S. Pat. No. Des. 288,116, issued Feb. 3, 1987.
A unique design in irrigation gate valves is shown in U.S. Pat. No. 3,033,514, issued May 8, 1962, in which there is shown a device having an enlarged apron portion which extends tangentially from a semicircular portion and projects to one side of the body a distance substantially equal to the radius of the axial opening in the body portion. This value is designed such that it will not turn or rotate in the opening. However, the device projects significantly into the pipeline such that it would significantly slow the passage of liquid through a pipeline. Further, this device must use a thickened, contoured gasket in order to be effectively leakproof.
Finally, there is shown in U.S. Pat. No. 3,981,061, issued Sep. 21, 1976 to Jackson, et al., a method for joining pipes, in which the device used to do that is shown as having a pair of lugs on its bottom, an indented neck portion for use in inserting the device in an opening in a main pipeline, a thickened, contoured gasket, a collar, a locking means, which is a locking nut which threads around the center pipe of the device and locks the whole together by depending on the lugs that have been inserted into the interior of the main pipeline.
This device is similar to the device of the instant invention. However, the device of the instant invention differs significantly by way of the following.
The device of the instant invention has two pair of lugs which are set out to the side of the device such that the middle of the device is open to allow minimal interference with the flow of liquid in the main pipeline, while the device of the '061 patent is constructed with essentially a full circle at the bottom which does cause interference with the flow to the branch point. Also, the lugs of the instant invention are designed as part of the saddle-shaped member of the device so that they do not project significantly down into the opening of the main pipeline, while the lugs of the '061 patent project significantly into the pipe opening and tend to impede the flow of liquid therein.
The device of the instant invention allows the use of an inexpensive flat washer while the device of the '061 patent requires a thickened, contoured gasket in order for the device to be effective. In other words, the device of the instant invention because of its saddle-shaped configuration, essentially mates with the inside edges of the opening of the main pipeline and and essentially fills the opening, thus, one does not need to use a thickened, contoured gasket in order for the device of the instant invention to work properly. Further, the device of the '061 patent requires an alignment tool for adapting the device to the main pipeline, and for centering the device in the opening in the main pipeline, while the device of the instant invention does not require such an alignment device. The device of the instant invention is configured such that the saddle-shaped member automatically aligns the device in the opening.
Finally, all of the features of the instant device can be had much more economically manfactured than the device of the '061 patent.